It can be upsetting when our pets get diagnosed with a disease – after all, they are part of the family. Some diseases require you, as an owner, to be extra vigilant and you may be required to change your pet’s routine. Let’s have a look at how to approach feeding a cat with an overactive thyroid.

What is an overactive thyroid?

An overactive thyroid is a disease in cats called hyperthyroidism. Hyper means increased function or overactive, and thyroid means affecting the thyroid gland. Put the two words together and you have hyperthyroid! The opposite of hyperthyroidism would be hypothyroidism, where the thyroid gland is underactive, and this is usually a condition seen in dogs.

The thyroid gland is located in the neck and sits on either side of the trachea, more commonly known as the windpipe. The thyroid gland is responsible for regulating an animal’s metabolism, by producing different hormones.

An overactive thyroid leads to excessive excretion of thyroid hormones which increases a cat’s metabolism. Hyperthyroidism usually affects older cats with symptoms including:

  • Increased appetite
  • Weight loss 
  • Aggression 
  • Poor coat condition 
  • Rapid heart rate 
  • Enlarged area around the neck

Feeding your cat with an overactive thyroid

You may have noticed that your cat is always ravenous and this may have been what prompted you to take them to your vet in the first place. Feeding a cat with hyperthyroidism requires extra consideration in order to support and manage their condition.


Consult your veterinary surgeon to see if medication or a change of diet is required.


Try to treat the condition with homemade remedies.


Offer a balanced diet that is appropriate for your cat’s age and condition. Their diet should be low in iodine, as an excess of iodine can worsen the condition. Speak to your vet if you’re unsure.


Attempt to ‘fill your cat up’ with food due to their hunger levels.


Offer regular, smaller-sized meals split over the course of the day. This will control their hunger and support their metabolism.


Feed exclusively raw food. A hyperthyroid cat will benefit much more from a prescription or a veterinary-recommended diet.


Provide plenty of fresh water for your cat, as hyperthyroid cats usually have excessive thirst.


Skip the vet visits. Often, your cat will require blood tests every 3 – 6 months to ensure that their thyroid level is well controlled. 


Keep an eye out for the development of food allergies. Hyperthyroid cats can often develop food sensitivities as a secondary condition.

What are the treatment options for hyperthyroidism?

You may be offered a few different treatment options for your cat that is suffering from hyperthyroidism. 


Your vet may prescribe your cat oral medication, such as tablets, or a gel that can be applied to your cat’s ear. These medications help to reduce the production of excessive thyroid hormones.

Radioactive iodine therapy

Some veterinary practices may be able to offer this treatment in-house or you may be referred to a specialist clinic. Radioactive iodine therapy involves giving your cat an injection that is highly effective and usually curative of the condition.

Thyroidectomy surgery 

Your veterinary surgeon may suggest complete surgical removal of the thyroid gland. This would eradicate the hyperthyroidism, but could potentially lead to secondary complications. Your vet would discuss this option with you thoroughly before you make your decision. 

Prescription diet 

In some less severe cases of hyperthyroidism, your vet may advise that thyroid levels can be controlled through a prescription diet. This may be particularly useful if other options are not accessible. 

Final thoughts on hyperthyroid in cats

Hyperthyroidism is a common condition that most veterinary practices diagnose and treat regularly. If you are unsure of how to feed your hyperthyroid cat, then always ask your veterinary surgeon for advice. The nursing team at the practice may also be able to support you and offer you advice on how to administer thyroid medication, as well as discussing diets that are available to you.

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